Allow missing FilePath when expanding macros

[zbynek]

Sometimes it's useful to run the tm step even if there is no active node/workspace. Instead of checking that FilePath is present upfront, check it only while expanding a macro that needs it.

Testing done

Checked that the Build Failure Analyzer macro expands properly after all connections to nodes are stopped.

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• [n/a] Link to relevant issues in GitHub or Jira
• [n/a] Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[slide]

Have you done any checking to see if there are token macros from other plugins that would need to be updated? This changes some of the public API, so we would need to make sure this doesn't break anything.

[zbynek]

Looks like there are 3 that use workspace in some way:
https://github.com/jenkinsci/email-ext-plugin/blob/2720b77c095d23a5ab820f477049b816ac31bf4f/src/main/java/hudson/plugins/emailext/plugins/content/JellyScriptContent.java#L32
https://github.com/jenkinsci/email-ext-plugin/blob/2720b77c095d23a5ab820f477049b816ac31bf4f/src/main/java/hudson/plugins/emailext/plugins/content/ScriptContent.java#L51
https://github.com/jenkinsci/email-ext-plugin/blob/2720b77c095d23a5ab820f477049b816ac31bf4f/src/main/java/hudson/plugins/emailext/plugins/content/TemplateContent.java#L20
I checked this list, which may not be 100% complete.

[slide]

The list is auto-generated, so it should be pretty accurate. We'll need to verify that this update works with email-ext at a minimum.

[zbynek]

@slide https://github.com/jenkinsci/email-ext-plugin/pull/576/files contains a test that shows that exception handling in EmailExt got slightly improved by this (before a NPE would be thrown that results in macro not expanding at all, now it expands to a useful error message). The other PR is still a draft because it depends on incremental build of this one, if this one is merged and released I'll update the other one.

[zbynek]

@slide can I do something to help get this merged?

[slide]

Let me take a look into it more on Monday. I just want to make sure that we don't break anyone.

[zbynek]

@slide could you please cut a release with the fix? My understanding of CD is that this PR needs a label and then another run on the default branch is needed, e.g. triggered by merging a housekeeping PR like this one.

[mwebber]

@zbynek @slide This doesn't work with email-ext.
As in "my jobs works with Token macro 400.v35420b_922dcb_, fails when I update to 442.v4f452dc3c7c0, and works again when I fall back.

It was doing this:

emailext(
  to: "${EMAIL_REPORT}",
  subject: "${enviroment_prefix}Asset Tracker New & Updated Resources ${start_date.toString()} to ${end_date.toString()}",
  mimeType: 'text/html',
  body: '${FILE,path="asset-tracker/resources_report_body.html"}',
)

The error reported in my pipeline was Error evaluating token: Error processing tokens
And it sends an email with the body containing the literal string ${FILE,path="asset-tracker/resources_report_body.html

[slide]

@mwebber Thanks for the report, I'll take a look ASAP.

[zbynek]

@mwebber sorry, hopefully fixed in #249

[mwebber]

@mwebber sorry, hopefully fixed in #249

Thanks for the quick fix @zbynek . I'll test as soon as it's released.

[zbynek]

@mwebber you can also download the plugin as .hpi from https://ci.jenkins.io/job/Plugins/job/token-macro-plugin/job/main/ and upload it to your instance via "adv (but I'm sure it will be released soon)

[mwebber]

@zbynek I tested with the just-released 444.v52de7e9c573d (with #249) and I can confirm that it fixed the problem for me.